In a key scene, Scottie and Madeleine visit California's Muir Woods National Park. (The scene was actually filmed at Big Basin Redwoods State Park.) Madeleine is enthralled by the giant redwoods, but suddenly Carlotta's spirit takes over. She walks to a cross-section of one of the trees that illustrates all the ring markings with the dates in history that the different rings were formed. She shows Scottie when "she" was born and when she died.
It's a creepy scene. The trees, whose average age in Muir Woods is about 600 years old, are meant to represent the ancient past. They're one of the film's many visual symbols of the past, like the old Mission Dolores and Mission San Juan Bautista, the Palace of the Legion of Honor, the graveyards that Madeleine visits. Even Madeleine's name is symbolic. In Marcel Proust's uber-famous memoir Remembrance of Things Past, the pastry that uncorks his 3000-page flood of memories was called a madeleine.